package java190904;

import java.util.Scanner;

public class Test19092503 {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		double price = 0;
		int weight = scanner.nextInt();
		if (weight >= 30) {
			System.out.println("Fall");
		}else {
			if (weight > 20) {
				price += (weight - 20) * 0.70;
				weight = 20;
			}
			if (weight > 10) {
				price += (weight - 10) * 0.75;
				weight = 10;
			}
			price += weight * 0.8;
			price += 0.2;
			System.out.printf("%.2f", price);
		}
	}

}
